High-precision patch curing process for six-dimensional force sensor

Abstract

The invention relates to the technical field of manufacturing processes of strain type force sensors, in particular to a high-precision patch curing process of a six-dimensional force sensor. In order to solve the problems that the conventional strain type force sensor is large in patch error and low in precision due to error superposition, and the strain gauges are distributed on a plurality of surfaces and need to be subjected to repeated patch curing to cause poor consistency, the invention provides the following technical scheme: the method comprises the following steps of: 1, adopting image visual alignment, and taking the grid wire positions of the strain gauges as references; temporarily bonding at least one group of strain gauges to a temporary substrate; 2, clamping the positioning mold according to opposite angles, and mounting the positioning mold on an elastic body of the six-dimensional force sensor; and 3, coating high-temperature curing glue on the strain gauge temporarily bonded on the temporary substrate. According to the invention, the measurement precision of the sensor can be obviously improved, the force sensing performance is ensured, the production efficiency can be improved, the cost is reduced, the technology practicability and economy are enhanced, and the application and development of the six-dimensional force sensor in the fields of humanoid robots and the like are powerfully promoted.

Description

Technical Field

[0001] This invention relates to the field of strain gauge force sensor manufacturing technology, and in particular to a high-precision patch curing process for a six-dimensional force sensor. Background Technology

[0002] With the rapid development of artificial intelligence and robotics, humanoid robots have gradually become a hot topic in research and application. Six-dimensional force sensors, as the core force sensing component of humanoid robots, play a crucial role in enabling robots to perceive external environmental forces and achieve precise control, accounting for up to 11% of their cost. Among various force sensors, strain gauge force sensors have become the mainstream choice for practical applications due to their wide applicability and practicality.

[0003] In the manufacturing process of strain gauge force sensors, attaching strain gauges is a crucial step. The main steps are: first, scribing lines on the sensor's elastomer; then, using high-temperature curing adhesive, aligning the strain gauge substrate with the scribing lines and attaching it to the elastomer; next, clamping it with a specialized fixture and curing it at room temperature or high temperature; finally, changing the face of the elastomer and repeating the attachment and curing steps. Existing scribing methods, which rely on substrate positioning rather than strain gauge wire positioning, make attachment errors unavoidable. Furthermore, these errors accumulate during manufacturing, resulting in current force sensors generally achieving an accuracy of only 0.3%. For six-dimensional force sensors, after multi-axis superposition, the accuracy generally drops to 1%, with even the highest accuracy only reaching 0.5%.

[0004] Furthermore, the complex structure of the six-dimensional force sensor's elastomer makes automated patching difficult, and manual patching is currently the most common method. Additionally, the strain gauges of the six-dimensional force sensor are distributed across six faces; existing processes require patching parallel opposing faces each time, necessitating three operations to complete the patching and curing process. This makes it difficult to guarantee the consistency of strain gauge patching and curing, further impacting the sensor's performance and quality. Therefore, this invention proposes a high-precision patching and curing process for six-dimensional force sensors. Summary of the Invention

[0005] The purpose of this invention is to address the problems in the background technology of existing strain gauge force sensors, such as large patching errors and easy error superposition leading to low accuracy, and the need for multiple patching and curing processes due to the distribution of strain gauges on multiple surfaces, resulting in poor patching and curing consistency. The invention proposes a high-precision patching and curing process for a six-dimensional force sensor.

[0006] The technical solution of this invention: a high-precision patch curing process for a six-dimensional force sensor, comprising the following steps:

[0007] Step 1: Using image visual alignment, at least one set of strain gauges is temporarily bonded to a temporary substrate based on the grid wire position of the strain gauges.

[0008] Step 2: Clamp the positioning mold diagonally and install it onto the elastic body of the six-dimensional force sensor;

[0009] Step 3: Apply high-temperature curing adhesive to the strain gauge temporarily bonded to the temporary substrate and install it into the positioning mold;

[0010] Step four: Use a clamp to hold the temporary substrate and positioning mold, and place them in a high-temperature furnace for curing.

[0011] Optionally, the six-dimensional force sensor includes a mounting ring, in which two sets of first elastic bodies are fixedly connected, a mounting block is disposed between the two sets of first elastic bodies, and at least one set of second elastic bodies is fixedly connected between the mounting block and the two sets of first elastic bodies respectively.

[0012] Optionally, the positioning mold is installed at the connection position between the first elastic body and the second elastic body.

[0013] Optionally, the positioning mold includes two sets of positioning plates, which are symmetrically arranged on both sides of the first elastic body. Two sets of first positioning grooves are respectively opened on the two sets of positioning plates, and multiple sets of first locking posts are arranged between the two sets of positioning plates. The multiple sets of first locking posts are respectively fixedly connected to the two sets of positioning plates.

[0014] Optionally, multiple sets of the first locking posts are located at the four corners of the first positioning groove, and each set of the first locking posts has one side that is in contact with the first elastic body. The positioning mold also includes a connecting plate disposed on the side of the first elastic body away from the second elastic body, and the connecting plate is fixedly connected between the two sets of the first locking posts.

[0015] Optionally, two sets of second positioning grooves formed by the first locking pins are respectively provided on both sides of the connecting plate.

[0016] Optionally, the two sets of positioning plates are respectively fixedly connected to connecting plates on the side near the second elastic body, and the connecting plates are provided with at least one set of third positioning grooves.

[0017] Optionally, two sets of second locking posts are provided between the two sets of connecting pieces. The two sets of second locking posts are fixedly connected to the two sets of connecting pieces respectively. The opposite side of the two sets of second locking posts is in contact with the second elastic body. The connecting pieces and the second locking posts form a fourth positioning groove.

[0018] Optionally, a positioning angle is provided at one corner of the temporary substrate, and positioning blocks corresponding to the positioning angle are provided inside the first positioning groove, the second positioning groove, the third positioning groove and the fourth positioning groove.

[0019] Optionally, the shape of the fixture corresponds to that of the positioning mold.

[0020] In summary, this application includes at least one of the following beneficial technical effects:

[0021] This invention achieves precise control over the installation position and orientation of strain gauges by using a precisely designed positioning mold, replacing traditional scribing positioning with structures such as positioning grooves and locking pins, and coordinating the positioning angles of the temporary substrate with the corresponding positioning blocks. At the same time, it adopts image vision alignment technology to overcome the limitations of manual alignment accuracy, effectively avoid error superposition, and significantly improve the accuracy of the six-dimensional force sensor from the current general level, ensuring the accuracy and stability of its force sensing performance.

[0022] The high-temperature curing process further shortens the adhesive curing time, and the fixtures, positioning molds, and temporary substrates can be cleaned and reused. This improves production efficiency while reducing material consumption and production costs, enhancing the practicality and economy of the process.

[0023] In summary, this invention can significantly improve sensor measurement accuracy, ensure force sensing performance, increase production efficiency, reduce costs, enhance process practicality and economy, and strongly promote the application and development of six-dimensional force sensors in fields such as humanoid robots. Attached Figure Description

[0024] Figure 1 A schematic diagram of a high-precision patch curing process for a six-dimensional force sensor is provided.

[0025] Figure 2 This is a schematic diagram of the structure of a six-dimensional force sensor;

[0026] Figure 3 This is a schematic diagram of the temporary substrate structure;

[0027] Figure 4 This is a schematic diagram of the positioning plate;

[0028] Figure 5 This is a structural schematic diagram of the connecting piece;

[0029] Figure 6 This is a schematic diagram of the structure of two sets of second elastic bodies;

[0030] Figure 7 yes Figure 6 A schematic diagram of the structure of the positioning plate;

[0031] Figure 8 yes Figure 6 Schematic diagram of the middle connecting piece;

[0032] Figure 9 This is a schematic diagram showing two sets of strain gauges mounted on the side of a temporary substrate;

[0033] Figure 10 yes Figure 9 A schematic diagram of the temporary substrate.

[0034] Figure label:

[0035] 1. Six-dimensional force sensor; 11. Mounting ring; 12. First elastic body; 13. Mounting block; 14. Second elastic body;

[0036] 2. Positioning mold; 21. Positioning piece; 22. First positioning groove; 23. First retaining post; 24. Connecting plate; 25. Second positioning groove; 26. Connecting piece; 27. Third positioning groove; 28. Second retaining post; 29. ​​Fourth positioning groove;

[0037] 3. Temporary substrate; 31. Positioning angle;

[0038] 4. Strain gauges. Detailed Implementation

[0039] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0040] The components of the embodiments of the invention described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0041] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] Example 1

[0045] like Figure 1 , Figure 2 , Figure 3 , Figure 9 as well as Figure 10 As shown, the present invention proposes a high-precision patch curing process for a six-dimensional force sensor, comprising the following steps:

[0046] Step 1: Clean the area on the six-dimensional force sensor 1 where strain gauges 4 are attached to facilitate adhesion. Thoroughly removing surface impurities and oil significantly improves the adhesion between the strain gauges 4 and the sensor surface, laying the foundation for subsequent high-precision patching. The six-dimensional force sensor 1 includes a mounting ring 11, with two sets of first elastic bodies 12 fixedly connected within the ring. A mounting block 13 is positioned between the two sets of first elastic bodies 12, and a set of second elastic bodies 14 is fixedly connected between the mounting block 13 and each of the two sets of first elastic bodies 12. Using image-based visual alignment, at least one set of strain gauges 4 is temporarily bonded to a temporary substrate 3, based on the grid wire position of the strain gauges 4. Multiple sets of strain gauges 4 are then temporarily fixed to the sides of multiple sets of temporary substrates 3 using positioning adhesive, achieving precise alignment of the strain gauges 4. Utilizing advanced image-based visual technology overcomes the accuracy limitations of traditional manual alignment, greatly improving the alignment accuracy between the strain gauges 4 and the temporary substrates 3, ensuring accurate subsequent patching. The positioning adhesive uses solvent-based adhesives such as neoprene glue and 502 glue. After the solvent evaporates, an adhesive layer is formed. 502 glue can even cure instantly. At the same time, the bonding strength drops sharply after being baked at high temperature, and it is easy to separate after temporary bonding.

[0047] Step two: The positioning mold 2 is clamped diagonally and installed onto the elastic body of the six-dimensional force sensor 1. The positioning mold 2 is installed at the connection position between the first elastic body 12 and the second elastic body 14. The positioning mold 2 facilitates positioning during the installation of the strain gauge 4. The precise installation of the positioning mold 2 can effectively avoid the errors caused by traditional scribing positioning, and achieve precise control over the installation position of the strain gauge 4.

[0048] Please see Figure 4 and Figure 5The positioning mold 2 includes two sets of positioning plates 21, symmetrically arranged on both sides of the first elastic body 12. Each of the two sets of positioning plates 21 has two sets of first positioning grooves 22. After the first positioning grooves 22 are fitted into the first elastic body 12, the temporary substrate 3 can be easily installed into the first positioning grooves 22, thereby fixing the strain gauge 4 onto the first elastic body 12. This structural design enables rapid and precise positioning and installation of the strain gauge 4 onto the first elastic body 12. Multiple sets of first locking posts 23 are arranged between the two sets of positioning plates 21. These first locking posts 23 are fixedly connected to the two sets of positioning plates 21 and are located at the four corners of the first positioning grooves 22. Each set of first locking posts 23 has one side fitted into the first elastic body 12, thus securing the positioning plate 21 to the side of the first elastic body 12. The first locking posts 23 ensure that the positioning plate 21 is stably fixed to the side of the first elastic body 12, preventing displacement during installation and ensuring positioning accuracy. The positioning mold 2 also includes a connecting plate 24 disposed on the side of the first elastic body 12 away from the second elastic body 14. The connecting plate 24 is fixedly connected between two sets of first locking posts 23. Two sets of second positioning grooves 25 formed by the first locking posts 23 are respectively disposed on both sides of the connecting plate 24. The second positioning grooves 25 are used to install strain gauges 4 on the other two surfaces of the first elastic body 12. The presence of the second positioning grooves 25 enables precise positioning and installation of strain gauges 4 on multiple surfaces of the first elastic body 12, effectively improving the efficiency and consistency of the patching. Two sets of positioning pieces 21 are fixedly connected to connecting pieces 26 on the side of the second elastic body 14. A set of third positioning grooves 27 are opened on the connecting pieces 26. The third positioning grooves 27 facilitate the installation of strain gauges 4 onto the side of the second elastic body 14 with the help of the temporary substrate 3. At the same time, the side of the positioning piece 21 can also be provided with mounting grooves that correspond to the third positioning grooves 27, which are used to install a longer temporary substrate 3 for simultaneous installation of two sets of strain gauges 4. This makes the installation of strain gauges 4 on the side of the second elastic body 14 more convenient and accurate, reducing installation errors. Two sets of second locking posts 28 are provided between the two sets of connecting pieces 26. The two sets of second locking posts 28 are fixedly connected to the two sets of connecting pieces 26 respectively. The opposite side of each set of second locking posts 28 is in contact with the second elastic body 14. The placement of the second locking posts 28 facilitates the connection pieces 26 being secured to the second elastic body 14. This ensures the stable installation of the connecting pieces 26 and guarantees the reliability of the positioning of the strain gauge 4 on the side of the second elastic body 14. Simultaneously, the T-shaped structure formed by the positioning piece 21 and the connecting piece 26 corresponds to the T-shaped structure formed by the first elastic body 12 and the second elastic body 14. This corresponding structural design further enhances the compatibility between the positioning mold 2 and the sensor, improving the overall positioning effect. The connecting piece 26 and the second locking posts 28 form a fourth positioning groove 29, which is used to install the strain gauge 4 on the other two surfaces of the second elastic body 14.A positioning angle 31 is provided at one corner of the temporary substrate 3. Positioning blocks corresponding to the positioning angle 31 are provided inside the first positioning groove 22, the second positioning groove 25, the third positioning groove 27, and the fourth positioning groove 29. The positioning angle 31 and the positioning blocks are designed to ensure that the strain gauge 4 is installed in the correct direction. This ensures the accurate installation direction of the strain gauge 4 from multiple dimensions, avoiding the problem of sensor performance degradation due to incorrect orientation.

[0049] Step 3: Apply high-temperature curing adhesive to the strain gauge 4 temporarily bonded to the temporary substrate 3, and install it into the positioning mold 2. The high-temperature curing adhesive is epoxy resin, which is cured after high-temperature baking to ensure that the strain gauge 4 is fixed on the six-dimensional force sensor 1.

[0050] Step four: Apply a polyethylene film to the outside of the positioning mold 2 and allow it to cure initially at room temperature to prevent the adhesive from sticking to the fixture. After initial curing, remove the polyethylene film, and use the fixture to hold the temporary substrate 3 and the positioning mold 2, then place them in a high-temperature oven for curing. The fixture corresponds to the shape of the positioning mold 2 to ensure tight contact between the strain gauge 4 and the six-dimensional force sensor 1. The use of high-temperature curing adhesive and the appropriate fixture ensures a firm and tight fit between the strain gauge 4 and the sensor, effectively reducing the gap between the plates and improving the stability of the sensor performance.

[0051] Step 5: After the high-temperature curing adhesive has cured, remove the six-dimensional force sensor 1, and disassemble the fixture, positioning mold 2, and temporary substrate 3. Clean the fixture, positioning mold 2, and temporary substrate 3 for later use, and clean the residual positioning adhesive on the surface of the strain gauge 4. This completes the high-precision mounting of the sensor. Furthermore, the fixture, positioning mold 2, and temporary substrate 3 can be reused through recycling and cleaning, reducing production costs and improving resource utilization.

[0052] Example 2

[0053] like Figures 6 to 8 As shown, based on Embodiment 1, the structure of the six-dimensional force sensor 1 and the positioning mold 2 are further optimized. Two sets of second elastic bodies 14 are fixedly connected between the mounting block 13 and the two sets of first elastic bodies 12, respectively. Compared with Embodiment 1, increasing the number of second elastic bodies 14 can further improve the force sensing sensitivity and stability of the six-dimensional force sensor 1, enhance its ability to capture and feedback complex force signals, and better meet the requirements of high-precision measurement.

[0054] Regarding the structure of the positioning mold 2, the connecting piece 26 has two sets of third positioning grooves 27. Compared to the single third positioning groove 27 in Embodiment 1, the two positioning grooves can correspond to the two sets of second elastic bodies 14 respectively. During the patching operation, the temporary substrate 3 can be used simultaneously to install strain gauges 4 on the sides of the two sets of second elastic bodies 14 respectively. This structural design not only significantly improves the patching efficiency, transforming the original operation of patching the side of a single second elastic body 14 into a synchronous operation, reducing the patching process time, but also better ensures the consistency of the installation of strain gauges 4 on the sides of the two sets of second elastic bodies 14, effectively reducing the error caused by batch patching, ensuring the balance and stability of the force sensing performance of the sensor in multiple directions, thereby improving the overall measurement accuracy and reliability of the six-dimensional force sensor 1.

[0055] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A high-precision patch curing process for a six-dimensional force sensor, characterized in that, Includes the following steps: Step 1: Using image visual alignment, at least one set of strain gauges (4) are temporarily bonded to the temporary substrate (3) based on the grid wire position of the strain gauge (4); Step 2: The positioning mold (2) is clamped diagonally and installed onto the elastic body of the six-dimensional force sensor (1); Step 3: Apply high-temperature curing adhesive to the strain gauge (4) temporarily bonded to the temporary substrate (3) and install it into the positioning mold (2); Step 4: Use a clamp to hold the temporary substrate (3) and the positioning mold (2) and place them in a high-temperature furnace for curing.

2. The high-precision patch curing process for a six-dimensional force sensor according to claim 1, characterized in that, The six-dimensional force sensor (1) includes a mounting ring (11), in which two sets of first elastic bodies (12) are fixedly connected, and a mounting block (13) is provided between the two sets of first elastic bodies (12). At least one set of second elastic bodies (14) is fixedly connected between the mounting block (13) and the two sets of first elastic bodies (12).

3. The high-precision patch curing process for a six-dimensional force sensor according to claim 2, characterized in that, The positioning mold (2) is installed at the connection position between the first elastic body (12) and the second elastic body (14).

4. The high-precision patch curing process for a six-dimensional force sensor according to claim 3, characterized in that, The positioning mold (2) includes two sets of positioning pieces (21), which are symmetrically arranged on both sides of the first elastic body (12). Two sets of first positioning grooves (22) are respectively opened on the two sets of positioning pieces (21). Multiple sets of first locking posts (23) are arranged between the two sets of positioning pieces (21), and the multiple sets of first locking posts (23) are fixedly connected to the two sets of positioning pieces (21).

5. The high-precision patch curing process for a six-dimensional force sensor according to claim 4, characterized in that, Multiple sets of first locking posts (23) are located at the four corners of the first positioning groove (22). Each set of first locking posts (23) has one side that is in contact with the first elastic body (12). The positioning mold (2) also includes a connecting plate (24) disposed on the side of the first elastic body (12) away from the second elastic body (14). The connecting plate (24) is fixedly connected between the two sets of first locking posts (23).

6. The high-precision patch curing process for a six-dimensional force sensor according to claim 5, characterized in that, The connecting plate (24) has two sets of second positioning grooves (25) formed by the first locking post (23) on both sides.

7. The high-precision patch curing process for a six-dimensional force sensor according to claim 6, characterized in that, Two sets of positioning pieces (21) are respectively fixedly connected to a connecting piece (26) on the side near the second elastic body (14), and the connecting piece (26) is provided with at least one set of third positioning grooves (27).

8. The high-precision patch curing process for a six-dimensional force sensor according to claim 7, characterized in that, Two sets of second locking posts (28) are provided between the two sets of connecting pieces (26). The two sets of second locking posts (28) are fixedly connected to the two sets of connecting pieces (26) respectively. The opposite side of the two sets of second locking posts (28) is in contact with the second elastic body (14). The connecting pieces (26) and the second locking posts (28) form a fourth positioning groove (29).

9. The high-precision patch curing process for a six-dimensional force sensor according to claim 8, characterized in that, A positioning angle (31) is provided at one corner of the temporary substrate (3), and positioning blocks corresponding to the positioning angle (31) are provided on the inner side of the first positioning groove (22), the second positioning groove (25), the third positioning groove (27) and the fourth positioning groove (29).

10. The high-precision patch curing process for a six-dimensional force sensor according to claim 9, characterized in that, The shape of the clamp corresponds to that of the positioning mold (2).

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